It will get you to the point where you can say, "yes that kind of sounds like an AC30" if you've played a real AC30 before, but it is kind of like building a model car instead of buying the real thing, and then saying "yeah, it looks like a real car." The AC30 is certainly not as versatile as a modelling amp, but it has the tone in spades in every setting. It is VERY touch responsive which the modelling amps rarely are. The key to an AC30 though is the Celestion Blue speakers....nothing else quite sounds as good, so make sure if you try one out that you use one with the Celestion Blue speakers in it, or you won't get the full effect.
I guess I could put it this way. When the modelling amps first came out, I gave them a try to see how they sounded. All the features and sounds they have are pretty cool for bedroom use, but then when you go to play live they either get buried in the mix, or they don't have the touch and feel of the real thing so you don't get as inspired with your playing. The Vox modelling amps are better than the others since they have a real tube in there, but its still not as good as the real thing.
Actually, its very much like that movie with Stallone where he's frozen and then waken back up in the future to catch a criminal, and the population has changed and they never do anything real anymore. So the girl asks Stallone if he wants to have sex, and then they proceed to have virtual sex with headsets and visors. Of course he doesn't want to do that because its not as good as the real thing, and he knows what the real thing is. So kind of a colorful description I guess, but the point is that you need to find out how the real thing compares to what you're using, and then you can make your own decision.
The AC30 is one of those amps that is a classic, and so its kind of an investment. I know that my 1993 Korg AC30 is pretty much still worth what I paid for it new, if not worth a little more, and this is 13 years later. So it has been worth it from a financial point of view, not to mention that I get to enjoy playing it very much too. I can't wait until I get my new 330/12BBR so I can try that through it, but it sounds great with my 230, my Strat, my custom guitar with humbuckers, my brother's Gibson with P90's, my Danelectro, etc. You get the point...it sounds good with everything!